Centerless grinder



Dec. 25, 1951 J. W. SMITH CENTERLESS GRINDER 2 SHEETS-SHEET 1 Filed July9, 1949 fis i Jam mama/l A'ITORNEYS Dec. 25, 1951 J, w, s g 2,579,520

CENTERLESS GRINDER Filed July 9, 1949 2 SHEETS-SHEET 2 INVENTOR John hTSml iiv Patented Dec. 25, 1951 UNITED STATES I PATENT OFFICE CENTERLESSGRINDER Application July 9, 1949, Serial No. 103,816

15 Claims.

1 My invention relates to a centerless grinder and more particularly toa centerless grinder for grinding blanks having profiles which it hasheretofore been impossible to centerless grind by what is substantiallythe through-feed method.

It is the principal object of the invention to provide a method of andapparatus for the generally continuous centerless grinding of profiledarticles, such, for example, as barrel rollers and similar articleswhich it has heretofore been impossible to centerless grind in agenerally continuous manner.

Other objects and various features of novelty and invention will behereinafter pointed out or will become apparent to those skilled in theart.

In the drawings which show, for illustrative purposes only, a preferredform of the invention- Fig. 1 is an end View in elevation of a simpleform of centerless grinder, illustrative of the invention;

Fig. 2 is a side view of the regulating wheel and feed mechanism, viewedsubstantially in the direction of the arrows on line 2--2 of Fig. 1;

Fig. 3 is a fragmentary plan view of grinding and regulating wheelsillustrating features of the invention;

Figs. 4, 5 and 6 are enlarged, fragmentary, sectional views of thegrinding and regulating wheels showing the work :blank beingprogressively ground from cylindrical to generally barrel shape;

Fig. 7 is a fragmentary end View, similar to Fig. 1, but illustrating aslight modification;

Fig. 8 is a side view in elevation of the regulating wheel shown in Fig.'7.

The centerless grinder may consist of a grinding wheel 5, a regulatingwheel 6, a work sup- In the particular illustration of Figs. 1 to 6, theregulating wheel is arranged to be moved away from the grinding wheel,which latter is carried by the main frame of the machine, as heretoforenoted. As illustrated, the regulating wheel 6 is rotatably mounted inthe slidable base I n, which base H! is itself adjustably mounted on asliding sub-base l I, and an adjusting screw 12 connects the bases l0and I I to provide for adjustment of the regulating wheel relatively tothe grinding wheel. The sliding sub-base H may be pivotally attached atl3 to the upper end of a lever l4 pivoted at l5 to ears I6, dependingfrom the main base 9. The lever I4 may be actuated by a cam H, which isrotatably mounted on a shaft [8, which shaft and the shaft [9 of theregulating wheel are driven in unison. The cam l! is of such form thatduring a small portion of the rotation of the regulating wheel 6, thelever is rocked so as to pull the regulating wheel back away from thegrinding wheel 5. The interval during this withdrawing of the regulatingwheel from the grinding wheel, in accordance with my improved method, isused for transferring work from one part of the grinding and regulatingwheel to another part for successive grinding operations, as will belater described. The regulating wheel is again :moved up toward thegrinding wheel by the cam ll; it may be moved up and then dwell or itmay be moved very gradually throughout the grinding operation so as toprovide a continuous feed.

i Feed may also result from gradually camming port or blade I, and, ifdesired, a top work support 8. It is common practice in the centerlessgrinding art to move the grinding wheel or the regulating wheel forseparating the two in the infeed method of grinding. Generally speaking,it is immaterial Whether the grinding wheel is moved away from theregulating wheel or the regulating wheel moved away from the grindingwheel, the object being merely to separate the two wheels so that workblanks may be moved without coming in contact with the grinding wheelduring the feed movement of the work pieces. I provide means forseparating the wheels and in the form illustrated the grinding wheel 5is rotatably mountedon the base or foundation 9, and the regulatingwheel 6 is mounted on the slide I 0 slidable on the base 9.

the holding surfaces on the regulating Wheel.

In accordance'with my invention, the regulating wheel and the grindingwheel have respectively opposed holding and grinding surfaces arrangedfor the grinding of the profil on the object to be ground. For example,if barrel rollers are to be ground, the grinding wheel has a pluralityof grinding surfaces profiled so as to progressively grind the surfaceof a blank into barrel roller form. The regulating wheel has holdingsurfaces which may be more or less profiled so as to hold the workblanks while being ground.

As shown particularly in Figs. 3 to 6,

the grinding wheel has a plurality of grinding surfaces 20, 2|, 22, 23,24. "These grinding surfaces are circumferentially continuous and a eseparate and. in generally radial planes; that is to say, the grindingsurfaces 20 to 24 are not spiral but extend around the grinding wheel ingenerally radial planes. The surfaces are profiled so as to eventuallygrind the barrel roller 211111318, as shown in Fig. 4, the grindingwheel has side grinding surfaces 25 corners 01f of a cylindrical rollerblank. The holding surface on the regulating wheel, which is oppositethe grinding surface 2t, may be a plane surface 26, as shownparticularly in Fig. 4. The next grinding surface 2! may be substantially as shown in Fig. 5, and if desired the corresponding holdingsurface 2? on the regulating wheel may be contoured as shown in Fig. 5.The contouring may be progressive until the final form is reached, as inFig. 6, when the grinding surface 2 5 will be profiled to the desiredbarrel shape, and the corresponding holding surface 28 on the regulatingwheel may be similarly contoured so that the blank will be accuratelyheld and accurately profiled to barrel roller shape.

An important part of my invention is the means or method of transferringwork blanks from one grinding surface or throat to the next. It has beenstated that the grinding surfaces are not spiral; neither are theholding surfaces .on the regulating wheel spiral, but both the holdingsurfaces and the grinding surfaces are in what may be termed generallyradial planes. In the form illustrated, the work pieces or blanks aretransferred from one grinding surface and corresponding holding surfaceto the next grinding and corresponding holding surface, by means on theregulating wheel which engage the blanks and shift the same from onegrinding surface to the next, whereby at each revolution of theregulating wheel a finished piece is discharged from the last grindingthroat, and by means to be explained, a new work blank is inserted intothe first grinding throat. The transfer of work pieces from one grindingthroat to the next is always done while the work pieces are out ofengagement with the grinding wheel.

blanks well out of the way of the grinding surfaces on the grindingwheel. The work supports 6 ands may be carried either by the regulatingwheel base or by the grinding wheel base, but, in any event, the workpieces or blanks will either roll away from the grinding wheel, as inFig. 1', or will be carried bodily by the regulating wheel and the worksupport if the latter is carried with the regulating wheel base.

In the form shown in Figs. 7 and regulating wheel at the transfer zoneis of re duced diameter, as indicated at 29, so that the work pieceswill simply roll down on the inclined work support '5 and intoengagement with the surfaces 29 and thus be removed from the zone of thegrinding surfaces of the grinding wheel 5: shown in Fig, '7.

One form of my improved transfer mechanism consists of cam means whichmay be the form of cam shoulders or ribs extending fromone holdingsurface to the next adjacent holding surface so that when the regulatingwheel is rotated, the work blanks supported on the work support will beengaged by the inclined cam shoulder means 39 and thus shifted fromonegrinding throat to the next successive the 25 to grind the grindingthroat until the last throat is reached, at which time a finished piecewill be ejected by the last transfer shoulder (ill.

Work blanks are preferably automatically fed to the first grindingthroat, and since such magazine feeds are well known in the art forfeeding work pieces to grinding throats for infeed grinding of pieces,such mechanism is indicated only diagrammatically in Fig. 2. in thature, work blanks are fed down a chute 31 onto a support which may be theplunger 32. Work blanks may ordinarily be stopped by an abutment 33.When the plunger 32 is drawn rearwardly or to the right, a work blankdrops down andupon the next movement of the plunger 32 to the left, thedropped work blank will be pushed to the left and into the firstgrinding throat, as will be understood. The feeding of blanks, asstated, is well understood in the art and has been only diagrammaticallyshown, but it will be understood that the actuation of the plunger '2will be in timed relation with the rotation of the regulating wheel sothat a work blank is forced into the first grinding throat at the propertime.

The grinding wheel and the regulating wheel may have the grindingsurfaces and the holding surfaces formed in various fashions andseparated as desired. In the form shown in the drawings, the grindingsurfaces 23 to 2d are formed in grooves which are bordered or defined bycircumferentially extending ribs or flanges. Thus, the camming shouldersor ribs 39' of the regulating wheel in efiect form continuations of theshoulders defining the grooves of the regulating wheel. The ribs 36 maybe somewhat narrower than the ribs defining the holding surfaces so asto provide the necessary clearance for the blanks. For ease ofmanufacture, the section 35 of the regulating wheel, which has thespiral or angular transfer" means. such as ribs 3E3, may be made as aseparate .part' set into: and forming a part of the regulating wheel.

In order to accurately hold .the work, blanks and insure a properholding thereof while being profiled, I prefer to form the work-support"l more or less as shown in Fig. 2, that to say, so that the varioussupporting surfaces corresponding to the various grinding throats willbe of a form corresponding to the general contour of the piece beingground in that throat.

The general operation of the machine will be understood by those skilledin the art. The grinding wheel is driven at the proper grinding speed,as is usual in centerless grinding, and the regulating wheel is drivenat the proper regulating wheel speed. The wheels are separated, or,rather, the work pieces are separated from the grinding wheel onceduring each revolution of the regulating wheel, and at that time theblanks are advanced one step; a finished work piece is ejected from thelast grinding throat and a new work blank is fed into the first grindingthroat. When the work pieces are again brought up to the profiledgrinding surfaces of the grinding wheel, the work blanks are ground andthe ground work pieces are again removed from the grinding wheel and arefed along one stepso that eventually the fed-in blank comes out of thelast throat as a finished ground piece. 7

The profiles of the various grinding surfaces may be maintained by anydesired or standard profiling devices now well known in the art.

While the invention has been described in considerable detail andpreferred forms illustrated,

it is to be understood that various changes may be made within the scopeof the invention as defined in the appended claims.

Iclaim:

1. In a centerless grinder, a grinding wheel and a regulating wheel,said grinding wheel having a plurality of separate circumferentiallycontinuous grinding profiles in adjacent parallel radial planes, saidregulating wheel having separate corresponding profile surfaces inadjacent parallel radial planes and continuous throughout a portion onlyof the circumference of said regulating wheel, said regulating wheelhaving generally spiral transfer means thereon for transferring workblanks from one profile to the next.

2. A centerless grinder comprising a grinding wheel and a regulatingwheel, said grinding wheel having a plurality of circumferentiallycontinuous grooves therein in adjacent parallel radial planes,sa'idgrooves being profiled to grind a desired shape on a work blank,said regulating wheel having a plurality of grooves cooperating withsaid grooves of said grinding Wheel to embrace work blanks between themand in the grooves, said grooves in said regulating wheel beingcontinuous throughout a portion only of the circumference of theregulating wheel, said regulating wheel having transfer shoulders fortransferring work pieces from one groove therein to the next.

3. In a centerless grinder, a regulating wheel and a grinding wheel,said grinding wheel having a plurality of circumferentially extendinggrooves in spaced apart parallel radial planes, said regulating wheelhaving a corresponding plurality of grooves in spaced apart parallelradial planes, a work rest for supporting work blanks held between thegrooves of the grinding wheel and regulating wheel, said regulatingwheel having angularly extending transfer means for transferring .workblanks from one groove to the next upon rotation of the regulatingwheel.

4. In a centerless grinder, a grinding wheel and a regulating wheel, awork rest between the wheels for supporting work blanks, said grindingand regulating wheels having opposed circumferentially extending workholding surfaces in spaced apart parallel radial planes, means forseparating said wheels to remove a work piece from the grinding surfaceof said grinding wheel, said regulating 'wheel having angularlyextending transfer means for transferring work pieces from one groove insaid regulating wheel to the next groove therein, whereby upon rotationof said regulating wheel work pieces resting on said work rest may betransferred from one groove in said regulating wheel to the next groovetherein, for the purpose set forth.

5. In a centerless grinder, a grinding wheel, a regulating wheel, saidgrinding wheel having a plurality of circumferentially continuousprofiled grinding surfaces, each surface being separate from the otherand located between generally radial planes, said regulating wheelhaving a plurality of separate holding surfaces for holding work piecesagainst the profiled grinding surfaces of said grinding wheel, a worksupport for supporting work pieces while being ground as aforesaid, andmeans for transferring work pieces from one profiled grinding surface tothe next profiled grinding surface, said re ulating wheel havingangularly extending shoulder means constituting the transfer mechanism,said regulating wheel having surfaces adjacent said shoulder means ofrelatively smaller diameter than the holding surfaces of said regulatingwheel, whereby work pieces may fall away from said grinding wheel whilebeing transferred from one profiled surface across the face of thegrinding wheel to the next profiled grinding surface.

6. In a centerless grinder, a grinding wheel and a regulating wheel,said grinding wheel having a plurality of profiled grinding surfaces inadjacent parallel radial planes, said regulating wheel having holdingsurfaces in corresponding adjacent parallel radial planes, said holdingsurfaces being continuous throughout a portion only of the circumferenceof said regulating wheel, and generally spiral transfer means on saidregulating wheel for transferring blanks from one holding surface to thenext adjacent holding surface, and a work support for supporting workblanks between said grinding and regulating wheels.

'7. In the combination defined in claim 6, means for separating saidgrinding and regulating wheels while the work blanks are transferredfrom the radial plane of one profiled grinding surface to the plane ofanother profiled grinding surface.

8. In the combination defined in claim l6, said regulating wheel at theregion of said transfer means being of reduced diameter, whereby workblanks being transferred as aforesaid may fall away from the grindingsurfaces While being transferred. 7

9. In a centerless grinder, a grinding wheel, a regulating wheel, and awork support for supporting blanks between said wheels, said grindingwheel having a plurality of circumferentially continuous profiledgrinding surfaces in parallel adjacent radial planes, said regulatingwheel having holding surfaces for holding work blanks on said grindingsurfaces for grinding profiles thereon, said regulating wheel havingangularly extending transfer camming surfaces for transferring workblanks from opposite one profiled grinding surface to another profiledgrinding surface.

10. In the combination defined in claim 9, means for separating saidgrinding and regulating wheels while work blanks are transferred fromthe radial plane of one profiled grinding surface to the radial plane ofanother profiled grinding surface.

11. In the combination defined in claim 9, said regulating wheel in theregion of said transfer means being of reduced diameter, whereby workblanks supported by said work support may fall away from said grindingsurfaces and into engagement with said reduced diameter surfaces,whereby said work blanks may be transferred from the plane of onegrinding surface to the plane of another grinding surface while beingout of contact with the grinding surfaces.

12. In a centerless grinder, a grinding wheel and a regulating wheel,said grinding wheel having a plurality of profiled grinding surfaces inadjacent parallel radial planes, said regulating wheel having holdingsurfaces for holding work while being ground by said profiled grindingsurfaces, a work support for supporting work blanks while being groundas aforesaid, said regulating wheel having transfer means fortransferring work pieces from one profiled grinding surface to the nextprofiled grinding surface upon rotation of said regulating wheel, andmeans for feeding work pieces to the grinding throat between theregulating wheel, the grinding wheel, and the work support.

13. In a centerless grinder for the centerless grinding Lo'f'generally'barrel-shaped rollers, a grinding wheel, a regulating wheeland work support between said wheels, said grinding wheel having aplurality of circumferentially continuous profiled grinding surfaces inadjacent parallel radial planes, each of said surfaces being profiled tocontribute to the grinding of a generally barrel-shaped roller, saidregulating Wheel having holding surfaces in generally radial planesextending throughout a portion only of the circumference of theregulating wheel for holding work blanks against said profiled grindingsurfaces, said regulating wheel having angularly extending transfer camsurfaces for engaging .blanksto transfer the same to successivbegrindingsurfaces as aforesaid, and means for separating the work'blanksfrom the grinding surfaces while the blanks are being transferred asafore- .said.

14. Ina: centerless grinder, a regulating Wheel :havinga plurality ofholding surfaces for holding a plurality of work blanks against agrinding 'wheel, saidholding surfaces extending throughout a portiononly of the circumferential extent of .said regulating wheel, andangularly extending shoulder means adjacent said surfaces for cammingwork pieces from one holdingsurface to. another holding surface uponrotation of said regulating wheel.

Number JOHN W. SMITH.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Name I Date 1,665,084 Caster Apr. 3,1928 1,846,661Vuilleumier Feb. 23, 1,932 1,886,579 Pew Nov. 8, 1932 1,948,113 IslerFeb. 20, 1934 1,973,922 Dumas Sept. 18; 1934 2,010,730 Lloyd Aug. 6,1935 2,413,880 Mason Jan. 7, 1947 2,436,252

Duncan Feb. 17, 1948

